Prometra A. H. Clark. 
Key to the Species of the Genus Prometra. 
a^ The first three pinnules are of the same length and character, but P, and the 
following pinnules are much shorter 
b' 1 6 — 2 1 (usually 18 — 19), cirrus segments; P, — P,( with 14 — 16 segments; 
arm length 55 mm. to 60 mm. (sout her n Japan) owstoni 
b- 14 — 15 cirrus segments; P, — P^ with 11 — 12 segments; arm length about 
30 mm. (Phil ip pine I s lands) loni:;ipi7iHa 
a" The first three pinnules are not of the same length 
b' Pj greatly elongated, becoming very slender and almost flagellate distally, 
nearly twice as long as Pj and P., which are of the same length, com- 
posed of 21 segments; arm length 90 mm.; cirri with 22 — 24 segments 
(Red Sea) chadtvicki 
\y Pj is longer than P^, which otherwise exactly resembles it; both are 
composed of 8 segments; arm length 18 mm.; cirri with 10— i i segments 
(A n d a m a n I s 1 a n d s) intermedia ') 
I . Prometra loiigipinna sp. nov. 
This species closely resembles P. owstoni-^ it may be briefly diagnosed as follows : 
The cirri have 14 — 15 segments of which the fourth and following are about as long 
as broad; the cirrus length is about 4 mm.. 
The arms are about 30 mm. long, resembling those of P. owstoni. 
P, is 5 mm. long, stift" and spine-like, composed of 11 — 12 segments of which the first 
is broader than long, the second one third again as long as broad, and the fourth and following 
two and one half to three times as long as broad ; the terminal three or four have prominently 
spinous distal ends. P., is 5 mm. long with 11 — 12 .segments, exactly resembling Pj. P^ is 
5 mm. long with 1 1 segments of which the outer are slightly more elongate than those of the 
preceding pinnules, and the fourth and following have everted and spinous distal ends. P, and 
the following pinnules are 3.5 mm. long with 10 segments, smaller and weaker than the 
preceding pinnules, though the component segments are of about the same proportions; the 
fourth and following have everted and spinous distal ends. The distal pinnules are 4.5 mm. 
long with 14 segments of which the third and following have slightly produced and finely 
spinous distal ends. 
The single specimen at hand was dredged in North Balabac Strait, Philippine Islands, 
in 58 fathoms ("Albatross" Stat. 5356; Cat. X" 35366 U.S. Xat. Mus.). 
No species of this genus was secured by the "Siboga", but it is desirable here to 
include a notice of it as it is one of the characteristic genera of the Indo-Pacific fauna. 
l) Oligomctra iiitumeiHa A. II. Clark, 1912. 
